Automatic merge from submit-queue

Don't panic if we hit a dangling symlink in mungedocs

I hit this because I have a dangling symlink, which would cause a panic.

Automatic merge from submit-queue

Log restclient request/response bodies using %#v.

These are now protobufs, so outputting them with %s dumps a large
amount of binary garbage into the log. %#v properly escapes exotic
characters.

Automatic merge from submit-queue

Retry when apiserver fails to listen on insecure port

The apiserver will already continually retry when it fails to bind to the secure port. However, with the insecure port it does not retry, and any failures cause the apiserver to exit.

This change makes it so the api-server will retry on both insecure/secure ports.

A use-case for this change is for self-hosting the api-server, particularly when you are only running a single copy in your cluster. In some bootstrap and upgrade scenarios - it's necessary to replace/pivot from an existing api-server on the same host -- where you need a new copy running before tearing down the old (which is problematic when the api-server will try to bind to an in-use port and exit).

Automatic merge from submit-queue

Add a customized ssh dialer that will timeout

Fix https://github.com/kubernetes/kubernetes/issues/23835.

@a-robinson @cjcullen @lavalamp 

Automatic merge from submit-queue

Add missing mungedoc run to hack/verify-munge-docs.sh.

Automatic merge from submit-queue

ConfigMap added to kube addon manager

fixes #28775

Automatic merge from submit-queue

[client-gen] Allow passing subresources in Patch method

Expand the Patch() method from:
```
Patch(name string, pt api.PatchType, data []byte)
```
to
```
Patch(name string, pt api.PatchType, data []byte, subresources ...string)
```

Continue on #27293. Fixes #26580.

cc @Random-Liu @lavalamp 

Automatic merge from submit-queue

add default flannel configuration for cni

I added a default flannel configuration for cni.

So hyperkube can be started with:
```
--network-plugin=kubenet
```
or with flannel:

```
--network-plugin=cni
--network-plugin-dir=/etc/cni/net.d
```

Requires update of cni binaries to 0.3.0 or later to work. See also https://github.com/kubernetes/kubernetes/issues/27603

This PR is intended to support multi-node Hyperkube 
https://github.com/kubernetes/kube-deploy/pull/115



CC @zreigz  

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Automatic merge from submit-queue

update resource builder error message to be more clear

release-note-none

The error message given by command line `kubectl get` is sometimes of no help / not clear on what must be corrected, e.g.：
`kubectl get pod pod/database-1-i10b9`
error: when passing arguments in resource/name form, all arguments must include the resource 

##### Steps to Reproduce:
1. Run command "$ kubectl get pod pod/database-1-i10b9"  

##### Actual Result:
Get unfriendly error message which is of no help:
"error: when passing arguments in resource/name form, all arguments must include the resource"

##### Expected Result:
Error message should recommend end user to run this cli in good grammar: "$ kubectl get pod database-1-i10b9" or "$ kubectl get pod/database-1-i10b9"

##### Before
"error: when passing arguments in resource/name form, all arguments must include the resource"

##### After
"error: there is no need to specify a resource type as a separate argument when passing arguments in resource/name form (e.g. `kubectl get resource/<resource_name>` instead of `kubectl get resource resource/<resource_name>`"

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Automatic merge from submit-queue

Stop eating panics

Fixes #28365

Update CHANGELOG.md.

Automatic merge from submit-queue

Better visibility to contributing docs.

<!--
Checklist for submitting a Pull Request

Please remove this comment block before submitting.

1. Please read our [contributor guidelines](https://github.com/kubernetes/kubernetes/blob/master/CONTRIBUTING.md).
2. See our [developer guide](https://github.com/kubernetes/kubernetes/blob/master/docs/devel/development.md).
3. If you want this PR to automatically close an issue when it is merged,
   add `fixes #<issue number>` or `fixes #<issue number>, fixes #<issue number>`
   to close multiple issues (see: https://github.com/blog/1506-closing-issues-via-pull-requests).
4. Follow the instructions for [labeling and writing a release note for this PR](https://github.com/kubernetes/kubernetes/blob/master/docs/devel/pull-requests.md#release-notes) in the block below.
-->

```release-note

```


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1. Updates the README.md to have a heading with the word "contribute", long
   time OSS contributors (or maybe I just do this) skim docs quickly and need
   a large call out to exactly what they are looking for.
2. The best resource I found was a developer guide that wasn't even linked in
   CONTRIBUTING.md, which seems like a shame so I made it right at the top!

Fix heading for previous releases on v1.3.0.

Automatic merge from submit-queue

Don't add analytics to .entries.

Automatic merge from submit-queue

Add SSH_OPTS to config ssh and scp port

Add SSH_OPTS support.This can change ssh and scp default port.

fixes #17934

Automatic merge from submit-queue

cluster/ubuntu/download-release.sh: if $KUBE_VERSION is set, use it.

```release-note
If $KUBE_VERSION is set in cluster/ubuntu/download-release.sh use that version, 
otherwise set it to the result of `get_latest_version_number`.
```

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Automatic merge from submit-queue

controller-manager support number of garbage collector workers to be configurable

The number of garbage collector workers of controller-manager is a fixed value 5 now, make it configurable should more properly

Automatic merge from submit-queue

Fix typo in pkg/runtime/serializer/codec_factory.go

Automatic merge from submit-queue

Unify logging in generators and avoid annoying logs.

@thockin regarding our discussing in the morning

@lavalamp - FYI

These are now protobufs, so outputting them with %s dumps a large
amount of binary garbage into the log. %#v properly escapes exotic
characters.

Automatic merge from submit-queue

kube-up: install new Docker pre-requisite (libltdl7) when not in image

Docker now has a dependency on libltdl7; we have to specify it manually
if we are installing docker using dpkg (vs using apt-get or similar,
which would pull it in automatically)

Fixes #28644

Automatic merge from submit-queue

More optimizations to scheduler throughput

Ref #28590

@davidopp @gmarek 

Automatic merge from submit-queue

Separate rate limiters for Pod evictions for different zones in NodeController

Ref. #28832

NodeController needs to be able to separately adjust rate-limits for eviction for different zones. This PR splits rate limiters.

cc @davidopp 

Automatic merge from submit-queue

Add custom-columns and custom-template-file to --help text

Automatic merge from submit-queue

Few more optimizations for scheduler

Ref #28590

@davidopp 

Automatic merge from submit-queue

Implement first version of indexing in cacher

This PR adds a first version of indexing in cacher.

It has a really significant impact on performance - __in empty 2000-node cluster, apiserver cpu usage drops by ~75%.__

Not for 1.3, but we need this soon after 1.3 is done.

@lavalamp @mqliang @davidopp @gmarek @kubernetes/sig-scalability